Continuous coupling element for slide fasteners

ABSTRACT

A continuous coupling element consists of an elongated filament of a synthetic resin or the like which is wound substantially helically to provide a multiplicity of turns with a row of spaced apart coupling heads formed along one longitudinal side thereof. Each of the turns further includes first and second shanks which when seen in a plan view, are curved arcuately in opposite directions, in such a manner that the first shanks of the respective turns partly overlap the second shanks of the preceding (or succeeding) turns and are connected to the second shanks of the succeeding (or preceding) turns via arcuate bights remote from the coupling heads. The continuous coupling element is to be fastened to one surface of a stringer tape as by a row of stitches extending along the overlapping portions of the first and second shanks.

United States Patent Yoshikawa Dec. 16, 1975 [75] Inventor: Kiichi Yoshikawa, Toyonaka, Japan [73] Assignee: Yoshida Kogyo K.K., Tokyo, Japan [22] Filed: Aug. 9, 1974 [21] Appl. No.2 496,195

[30] Foreign Application Priority Data Sept. 21, 1973 Japan 48-111093 [52] US. Cl. 24/205.16 C; 24/205.l3 C [51] Int. Cl. A44B 19/12 [58] Field of Search 24/205.13 C, 205.1 C,

[56] References Cited UNITED STATES PATENTS 2,299,230 10/1942 Hanson 24/205.13 C 3,047,924 8/1962 Wilcken 24/205.l3 C 3,149,389 9/1964 Steingruebner.... 24/205.l3 C 3,266,114 8/1966 Gerlach 24/205.13 C 3,423,803 1/1969 Frchlich 24/205.l3 C 3,609,827 10/1971 Heimberger 24/205.13 C 3,815,181 6/1974 Sekine 24/205.13 C

FOREIGN PATENTS OR APPLICATIONS 592.673 2/1960 Canada 24/205.13 C

Primary ExaminerBernard A. Gelak Attorney, Agent, or FirmBucknam and Archer [57] ABSTRACT A continuous coupling element consists of an elongated filament of a synthetic resin or the like which is wound substantially helically to provide a multiplicity of turns with a row of spaced apart coupling heads formed along one longitudinal side thereof. Each of the turns further includes first and second shanks which when seen in a plan view, are curved arcuately v 2 Claims, 6 Drawing Figures U.S. Patent Dec. 16, 1975 3,925,859

FIG-1 |=|e.2

pstringer tapes.

cos'rmuous COUPLING ELEMENT Eon sunn- FASTENERS BACKGROUND or= THEINVENTION more Specifically to continuous coupling elements for slide fasteners of the so-called meandering or coil type ,.-shapes.1 A row. of spaced apart coupling'heads are formed along one longitudinal side of the turns of such continuous couplingelementso as tobe interfittable with a similar row of heads of a complementary cou- .plingelementHEach turn of the continuous coupling el-,

ement can be visuar-ized. asa pair of legs or Shanks-interconnected 'on one side by the coupling head and, on

the other side, joined by arcuate bights to a preceding and a succeedingturn respectively.

In ,the continuous coupling elements of the type,

under consideration, difficulties are encountered in relation to thewmaintenance of the desired pitch of the turns. .Thesedifficulties arise from the fact that according. to the prior art,,the desired intertum spacing is usu- 1 This invention relates generally to slide fasteners and ally-determined only by the bights interconnecting the shanks of the respective turns. However, in order to re-.-

ali ze a highdegree of coupling efficiency-in slide fasteners, it is of labsolut'e necessity that. .the individual turns of thecoritinuous coupling elements be faithfully;

maintained in the SUMMARY OF THE INVENTION I l t is, therefore, an object of this inventiont o'provide an improved continuous coupling element in the form of a substantially helically wound filament. of a syn. the'tic resin or the like, such that the tums of the filament can be strictly retained in their predetermined. spaced apart'positions on a stringertape to make poss-iir predetermined relativepositions on a stringer tape as by a row of stitches extending along the overlapping portions of the first and second shanks.

The features which are believed to be novel and characteristic of this invention are set forth in particular in the appended claims. The invention itself, however, as well as the additional objects and advantages thereof, will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate, by way of example only, some preferred embodiments of the invention and in which like reference characters denote like parts throughout the several views.

DESCRIPTION OF THE DRAWINGS FIG. 1 isa plan view of the continuous coupling element according to the novel concepts of this invention;

.FIG. 2 is a cross sectional view of the element shown in FIG. 1;

FIGS. 3 and 4 are views similar to FIG. 2 but each showing a possible modification in the cross sectional shape of the element;

FIG. 5 is also a view similar to FIG. 2 but showing a further possible modification in the cross sectional shape of the element with a core member inserted longitudinally therethrough; and

FIG. 6 is a plan view explanatory of the mode of attachment of the element of FIGS. 1 and 2 to a stringer tape.

DESCRIPTION OF THE PREFERRED I, EMBODIMENTS FIGS. 1 and 2 illustrate a preferred form of the continuous coupling element 10 for a slide fastener according tothis invention. The continuous coupling element 10 is composed of an elongated monofilament of a synthetic resin or the like which is wound into substantially helical or meandering configuration. Formed along one longitudinal side of the continous coupling element 10 ble theprovision of slide fasteners with a high degree of Another object of the invention is to provide a continuous coupling element of the character described which can be easily and positively fastened to a stringer tape as by a conventional stitching technique.

With these objects in view, this invention provides a continuous coupling element comprising an elongated filament wound substantially helically to provide a plurality of turns each consisting essentially of first and second shanks interconnected by a coupling head. When viewed in a plan view, the first and second shanks of each turn are curved arcuately so as to bulge toward a preceding and a succeeding turn respectively. Thus the first shanks of the respective turns are arranged in partly overlapping relationship to the second shanks of the preceding (or succeeding) turns and are joined to the second shanks of the succeeding (or preceding) turns via bights located remote from the coupling heads. By thus relating the shanks of each turn to those of the adjacent turns, the positional stability of the turns of the coupling element can be remarkably augmented when the same is fastened to one surface of are a series of spaced apart coupling heads 11 adapted for mating engagement with identical coupling heads, not shown, of a complementary coupling element. Each coupling head 11 also functions to interconnect first and second shanks 12 and 13 extending generally rearwardly therefrom.

According to the novel concepts of this invention, the first and second shanks 12 and 13 of an exemplary turn 14 of the continuous coupling element 10 are curved arcuately away from each other, as seen in a plan view as shown in FIG. 1, so as to protrude from the central axis of the exemplary turn 14 toward the adjacent turns over a maximum distance equal to substantially one-half of the pitch of the turns of this continuous coupling element. By the term central axis of the turn is meant, of course, that which is perpendicular to the longitudinal axis of the continuous coupling element 10.

Also as shown in FIG. 1, the first shank 12 of the exemplary turn 14 extends in partially overlapping relationship to the second shank 13a of a turn 14a adjoining the exemplary turn on one side thereof. The first shank 12 of the exemplary turn 14 is connected via an arcuate bight 15 to the second shank 13b of a turn 14b immediately adjoining the exemplary turn on the other side thereof, the said second shank 13b partially underlying the first shank of a turn 14c two pitches away from the exemplary turn. The second shank 13 of the exemplary turn 14., of course, partially underlies the first shank 12b of the turn 14b and is connected via an 3 arcuate bight 15 to the first shank 12a of the turn 14a.

It will be noted from the showing of FIG. 1 that the first shanks 12a, 12, 12b, 12c of the respective turns 14a, 14, 14b, 14c overlie the second shanks 13a, 13, 13b of the adjoining turns at their portions arranged along a stitching line S S, as later described in more detail.

When viewed cross-sectionally, each turn of the continuous coupling element may typically be teardropshaped as shown in FIG. 2. However, if desired, the first and second shanks 12 and 13 of each turn may be compressed toward each other at their end portions close to the bights 15, thereby shaping the turn into generally racketlike configuration as shown in FIG. 3. Altematively, one of the shanks (second shank 13 in the example shown in FIG. 4) of each turn may be formed in a straight line, whereas the other shank is bent as that shown in FIG. 2. It is also possible to provide an elliptic turn as shown in FIG. 5. In this latter case a suitable cord or like core member 16 may be inserted longitudinally through the respective elliptic turns of the continuous coupling element.

As illustrated in FIG. 6, the continuous coupling element 10 of FIGS. 1 and 2 can be stitched by sewing stitches 17 along the aforesaid line S S onto one surface of a stringer tape 18 so as to extend along one longitudinal edge thereof. Since the first shanks of the respective turns of this continuous coupling element overlie the second shanks of the adjoining turns along the stitching line S S in the manner previously set forth with reference to FIG. 1, the distance D between the shanks of the adjacent turns is maximized along this stitching line. Sufficient spacings 19 are thus formed for the passage of the needle in stitching the continuous coupling element 10 onto the stringer tape 18.

It may have been noted from the foregoing description that the first shank 12 of each turn 14 is not only arranged in partially overlapping relationship to the second shank 13a of one adjoining turn 140 but is connected via the bight to the second shank 13b of the other adjoining turn 14b partially underlying the first shank 120 of the turn 140 two pitches away from the exemplary turn 14. This configuration is in marked contrast to the prior art where the respective turns of continuous coupling elements have been sought to be retained in their predetermined spaced apart positions only by the bights interconnecting the shanks. It will therefore be apparent that the continuous coupling element according to the invention is capable of with- 4 standing stresses to which it is subjected to a materially greater extent than the prior art, with its individual turns positively maintained in their correct relative po- 'sitions throughout the prolonged periods of use of the slide fastener incorporatingsuch continuous coupling element.

Having thus described the several useful and novel features of the continuous coupling element according to the invention, it is believed that the many objects for which it was designed have been fully accomplished. However, while but a few of the various possible embodiments of the invention have been illustrated and described herein, certain additional modifications may well occur to those skilled in the art within the broad teaching hereof. The invention, therefore, should be interpreted to comprehend all such modifications remaining within the scope of the following claims.

What is claimed is:

1. In a slide fastener having a continuous coupling element attached to a stringer tape by stitches extending along a line of stitching the improvement which comprises a coupling element in the form of a substantially helically wound filament with the turns thereof forming a plurality of spaced apart coupling heads along one longitudinal side of said filament for mating engagement with identical coupling heads of a complementary coupling element, each of said turns of said filament having first and second shanks which are curved arcuately in opposite directions, so as to protrude from the central axis of the turn toward the adjacent turns over a maximum distance equal to substantially one-half of the pitch of said turns of said filament, said first shank of one exemplary turn being disposed in partially overlapping relationship to the second shank of the turn immediately adjoining said exemplary turn on one side thereof and being connected via a bight to the second shank of the turn immediately adjoining said exemplary turn on the other side thereof, the last mentioned second shank partially underlying the first shank of the turn two pitches away from said exemplary turn on said other side thereof, said continuous coupling element being stitched against one surface of the stringer tape, and said first shanks of said turns of said filament overlapping said second shanks of the adjoining turns along line of stitching. 2; The improvement as defined in claim 1, further c'ofnprising a core member extending longitudinally through said turns of said filament. 

1. In a slide fastener having a continuous coupling element attached to a stringer tape by stitches extending along a line of stitching the improvement which comprises a coupling element in the form of a substantially helically wound filament with the turns thereof forming a plurality of spAced apart coupling heads along one longitudinal side of said filament for mating engagement with identical coupling heads of a complementary coupling element, each of said turns of said filament having first and second shanks which are curved arcuately in opposite directions, so as to protrude from the central axis of the turn toward the adjacent turns over a maximum distance equal to substantially one-half of the pitch of said turns of said filament, said first shank of one exemplary turn being disposed in partially overlapping relationship to the second shank of the turn immediately adjoining said exemplary turn on one side thereof and being connected via a bight to the second shank of the turn immediately adjoining said exemplary turn on the other side thereof, the last mentioned second shank partially underlying the first shank of the turn two pitches away from said exemplary turn on said other side thereof, said continuous coupling element being stitched against one surface of the stringer tape, and said first shanks of said turns of said filament overlapping said second shanks of the adjoining turns along said line of stitching.
 2. The improvement as defined in claim 1, further comprising a core member extending longitudinally through said turns of said filament. 